Satellite communications involve transmission of electromagnetic waves. Electromagnetic waves can have small wavelengths and be transmitted at high frequencies in the gigahertz (GHz) range. Satellite antennas can produce focused beams of high-frequency electromagnetic radiation that allow for point-to-point communications having broad bandwidth and high transmission rates. One type of satellite antenna is a flat panel antenna. This type of antenna includes a number of panels or segments having dipoles or other radiating elements to receive and transmit electromagnetic waves. If the antenna elements are fed in series or if the antenna elements are distributed along the length of the feeding waveguide, as with a periodic leaky wave antenna, the feeding wave propagates along the aperture or area of a flat panel antenna and the power density distribution decays along the aperture as a result of radiation by the antenna elements. The power density distribution across the aperture of the antenna is desired to be as uniform as possible in order to maximize the aperture efficiency of the antenna.